Fluorescent lighting fixture



March l1, 1958 H. SMITH 2,826,583

FLUORESCENT LIGHTING FIXTURE Filed Aug. 1s, 1952 s sheets-sheet 1 Hai.,

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QM @www March 11, 1958 H. L. SMITH 2,826,683

FLUORESCENT LIGHTING FIXTURE Filed Aug.' 18, 1952 5 Sheets-Sheet 2 8f-w18 `\1. vf' S L: J

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H. L. SMITH FLUORESCENT LIGHTING FIXTURE 5 Sheets-Sheet 3 INVENTOR.

United States Patent FLUoREscnNr LIGHTING FIXTURE Herbert Lionel Smith, Brookmans Park, England, assgnor to Benjamin Electric Manufacturing Company, Des Plaines, lll., a corporation of Illinois Application August 18, 1952, Serial No. 305,002

4 Claims. (Cl. 240--51.11)

This invention relates to lighting fittings, and more particularly to translucent covers for openings in such fittings.

It is frequently required to provide closures for openings in lighting fittings. The present invention also makes use of a flexible translucent material, and in accordance with the invention there is provided a lighting fitting having an opening therein and a closure for said opening, of translucent resilient material, said closure having portions adapted to engage the two surfaces of the fitting adjacent the edges thereof defining the Opening, said closure being adapted to be inserted in said opening by flexing the closure and being retained in said opening by the resilience of the closure.

The invention also includes a lighting fitting having an opening therein and a closure for said opening of translucent resilient material, said closure having portions adapted to embrace the edges of the opening at opposite parts thereof, said closure being adapted to be inserted in said opening by flexing said opening and to be there positively retained by the resilience of the closure.

The invention further includes a lighting fitting having an opening in a substantially plane surface thereof, and a closure for said opening of translucent resilient material, the closure having a generally plane form with marginal portions separated in the direction normal to that plane and located at opposed parts of the closure, the closure being adapted to be inserted in the opening by flexing the closure to permit the said marginal portions to embrace opposed edges of the opening and thereby to retain the closure in the opening. l

The features of the invention will be more clearly apparent from the following description of lighting fittings embodying the invention, in conjunction with the accompanying drawings, in which:

Figure l is a longitudinal section through the upper part of an inverted trough reflector for a fluorescent lamp, which includes a top-lighting opening and a closur therefor.

Figure 2 is a section on the line 2 2 of Figure l.

Figures 3, 4 and 5 are respectively a plan view, end view and side View of the closure which is shown in position in Figures l and 2.

Figures 6, 7 and 8 are three corresponding views of an alterntaive form of closure.

Figure 9 is a section, similar to that of Figure 2, of a modified trough reflector having a masked top-lighting aperture and an appropriate closure.

Figures 10 and l1 are respectively plan and end elevational views cf the closure shown in position in Figure 9.

Referring firstly to Figures 1 and 2 of the drawings, there is shown the upper part of an inverted trough reilector 12 forming part 0f a lighting fitting for an elongated fluorescent lamp (not shown). The reflector is formed with two pairs of top-lighting openings 13 which extend longitudinally in the sides to permit light to pass upwardly out of the reflector. Each of these openings rice is provided with a removable translucent closure 14 of flexible plastic sheet material such as cellulose acetate or an acrylic resin. As here shown the openings 13 have parallel sides and rounded ends; the closures 14 have a corresponding shape but are of somewhat larger over-all six lugs 16 which lie in the plane of the central portion.`

In this way the flange 15 and lugs 16 are disposed in planes separated by a short distance in the direction normal to the plane of the central portion as shown in Figures 3 and 4, so that their surfaces may engage respectively the inner and outer surface of the edge of the opening in the reflector. In use the closures are sufficiently resilientfor `them to be flexed parallel with their longer axis and spring into position with the flange surface 15 engaging One-preferably the innersurface of the edge of the opening in the reflector and the lugs 16 engaging the other surface as shown in Figure l. They are thereby positively retained. A modified form of closure is shown in Figures 6, 7 and 8; in this case the closure is formed from a continuous strip of material having a section of the shape `shown in Figure 7 with a central portion 17 and spaced marginal portions 18 and 19. Such material can be made by extrusion in continuous strip form, as indicated by the dotted line 20 of Figure 6. The desired shape, such as that shown, can

be formed from the strip by punching. This closure can be inserted, as with that of Figures 3 to 5, by flexing the strip and then springing it into position in the opening 13, with the portions 18 on the one surface of the reflector and the portions 19 on the other.

In some installations the use of a lighting fitting such as that shown in Figures 1 and 2 may give rise to glare from the openings 13, particularly where the fitting is installed at a low height. To overcome this glare, whilst at the same time affording a measure of upward lighting, the fitting can be provided with a mask or shield, as shown in Figure 9. Such a masked opening can be provided with a closure in accordance with the invention, l

that shown in Figures 1 and 2 but in the inclined upper portion of the reflector 12 of which are formed two pairs of substantially rectangular openings 20. Along the length of the lower edges of these openings are light shields 21; these shields are disposed approximately vertically and are conveniently formed integrally with the reflector, by bending up, as shown, part of the material from the opening. t The top edge of the shield lies approximately on the same horizontal level as the upper edge of the opening.

This opening between the shield and the reflector is substantially completely closed by a closure 22, shown in Figures 10 and 11, and accordingly the closure is approximately rectangular in plan and trinagular in end view. This closure has a main portion 23, horizontal in use, and two integral triangular end portions 24. An interrupted flange 25 is formed round those edges of the closure which lie adjacent the body of the reflector 12 and like the flange 15 of the closure 14, the flange is interrupted by lugs, in this case lugs 26, along one edge thereof. The lugs 26 and flange 25 lie in parallel and slightly separated planes, so that the closure can embrace the edge of the opening, and slots 27 formed at the lower apices of the triangular ends 24 allow the edge of the opening adjacent the shield 21 to be gripped, as shown in Figure 9.

When thus applied to the opening in the reflector the forward part of the main portion 23 of each closure engages the top of the corresponding shield 21, and the forward parts of the triangular ends engage. the vertical ends of the shield. The partsV o f the closure which engage the shield are preferably'curved slightly, or shaped, as shown in Figures 9 and 1l.- This form of closure is fitted over an opening from" the inside of the reflector by exertingy lpressure inr an outward horizontal direction, flexing the closure and then springing it into position over the opening with the an'ges, lugs and notches engaging the appropriate surfaces ofthe rellector adjacent the top lighting opening.`

It will thus-beseen that the invention `provides a closure for the openings of Alighting fitting'reectol's Whichis simple to manufacture and convenientto remove and replacey when necessary.

Further'modifications-will be apparent to those skilled in the artfand itis desiredtherefore, that the invention. be `lirnitedonly by the scope Aof the appended claims.`

Having thus described V`ry'invention, what I. claim and desire to-seeureby LettersPatent is:

1. A lighting fixture for an elongated light bulb comprising a channel-like reector of downwardly reflecting sheet material having at least onev elongated opening therein for emitting light' from'said bulb in an upward direcf tion, anda detachable windowA of'light-transrnittant,-flexible and resilient plastic sheet'material closing said opening, said window having integral laterally displaced engaging` portions .extending fromI opposite sidesthereof'with certain of said-engaging portions lying substantiallyin the general plane of said window and 'other engaging portions oiset therefrom'a distance substantially equal to the thickness-*fofy thev reflector material defining `said opening, said engaging portions normally engaging the inner and outer surfaces yof the reflector material at opposite sides of the` opening to secure said window over said openingfand being disengageable lfrom the reflector to permit removal of said window fromy the reflector opening upon ilexing ofsaid window along a longitudinal axis.

2. A'lighting fixture-for an elongated lightl bulb com prisingy a channel-like'reector of downwardly reflecting sheet material having at-least one elongated opening therein for emitting lightfrom said bulb in an upward direction and a detachable-'window of light-transmittant, flexible and resilient-plastic sheet material closing said opening,said window having'integral engaging portions.' alternately displaced laterallyfromeach other extending y from opposite sides. thereof with certain of said engaging portions lying substantiallyv inthe general plane; of said window and other engaging vportions offset therefrom a distance substantially. equal to the thickness of the. rellectorz,

material defining said. opening, Said engaging portions.

normally engaging. the .innerqand outer 'facesA of the ref.

ector material atr Opposite sides. of;` the opening to secure said window over said opening andbeing disengageablef from the reector to permit removal of said .window lfrom the reflector opening upon flexing of said window along a longitudinaliaxis.

3. A lighting fixture for an, elongated light bulb cornprising a channeblike reilector of downwardly reflecting sheet material having at least one elongated opening therein for emitting light from said bulb in an upward direction, and a detachable window of light transmittant, flexible and. resilient. plastic. sheet ,material closing said opening, said windowv having integral laterally displaced engaging portions extendinafrom opposite. sidesthereot,

the embracing portions at eachside comprising `a -pair of substantially parallel continuous-flanges with one of' each pair of flanges lying substantially in the. general .plane of said window andthe other oilset therefrom a distance substantially equaltotthe thcknessof the rellector material defining said opening, said flanges normally engaging the inner and outer surfaces of the reflector material at opposite sides of the. opening. to secure said window over said opening and being disengageable. from the reilector, to permit removal of said window from the reflector opening upon tlexing ofsaid window along a longitudinal axis..

4; A lighting fixture Vfor an elongated light bulb cornprising ja "channel-like reilector of downwardly reilecting sheet material having atleast one elongated opening therein for emitting light from said bulb in an upward direction, andl av detachable window of light-transmittant, ilexi-v ble and resilient plastic sheetmaterial of substantially the sizeA and shape of said opening closing said opening, said'.

window having rintegral engaging portions alternately displaced laterally from eachother extending therefrom with certain of said, engaging portions comprising an uninterrupted Iperipheralflangelying substantially in the general plane ofr'said window and'other engaging portions at the sides oirsaid window comprising lugs opposite the-'interruptionsin said peripheral flange lying substantially ina plane generally4 parallel to the general plane of said window and oiset therefrom a distance substantially equal to the 'thicknessof the reflector material defining said opening, said engaging portions normally engaging the inner and outer surfaces of the reile'ctor material defining the opening therein to secure said window over said opening and being disengageable from the reilector to permit removall of Vsaid'vt/ indow from the reflector opening upon vilexing of said window along-a longitudinal axisg References .Cited inzthe tile of ythis patent 1 Y UNITEDv STATES PATENTS' 

